Implementing Real-Time Statistical
Analysis of Power Quality in a
Distributed Generating Environment
(multiple wind farm sites)
By Martin Boulay, Eng. (The Ohmega Group)
and Robert O’Reilly (Cooper Power Systems - Cybectec)
SCADA systems involved in a
wind farm project:
• Wind turbine SCADA.
• Substation SCADA.
Needs of the transporters
in general:
Case study, Hydro-Quebec’s
requirements since 2007:
• Time latency of less than 1 second for a
specific category of points.
• Time latency of less than 900 ms for the
states and alarms, 3 seconds for the real
time measurements and 10 minutes for
the statistical data.
• Utilization of a specified protocol of
communication.
• Meteorological tower data acquisition
system.
• Transmission company’s SCADA.
• Real time monitoring of the state of the
turbines and some devices of the substation.
• Teleprotection SCADA (In charge of
isolating a specific part of the transport/
distribution network in case of a fault).
• Real time monitoring of the alarms of the
substation.
• Statistical information from the weather
and the production.
• Distribution company’s data acquisition
system (That analyses the wind production
in function of its external parameters and
defines a model to use in the planning of its
available power from the production
companies).
• Custom calculation of some specific
information (ex.: Number of turbines
in a specific state).
• Conversion algorithm to standardize the
information from different turbine
manufacturers.
• 2 separated network interfaces to isolate
the SCADA LAN from the transporter’s
private link.
• Usage of the unsolicited reporting
functionality of the DNP3 protocol over
TCP/IP.
• Real time monitoring of 70 measurement
points from the substation and the
turbines.
• Statistical information that represents 50
points per met mast, 20 points per turbine
and 25 points in general in regards to the
production.
• A total of more than 1 700 points transmitted
for a wind farm of 60 turbines.
• Requirements of some specific
calculations derived from the information
that is available into the different systems
(vectorial statistics, available power seen at
the substation, at the turbines and for the
park at large, number of turbine stopped for
low temperature, high wind and low wind).
Needs of the producers:
• Centralisation of the different SCADA
systems on a site.
• High resolution archiving of the mission
critical information.
• Condition based monitoring when possible.
• Monitoring and archiving the raw data of
the critical information from the turbine
SCADA that usually, for most of the
manufacturer, archives on a 10 minute
average base.
• Possibility to export all the data to a
remote Control Center.
• Remote access to the system and
specially to the IEDs directly, to get a
remote support from the specialists
to the local team.
• Efficient system of alarm pager to
inform/alert the operation personnel.
• Redondancy on mission critical devices.
• Modem backup lines on routers and
gateways.
• Good understanding of its own needs
as well as the power company’s ones
to include the central SCADA system into
the initial construction of the wind farm
as much as possible.
SCADA Architecture Proposition:
(Case study of a wind farm that is connected
to Hydro-Quebec’s network)
This approach, centralised on the SMP gateway to
concentrate the data, pre-process the information
and be the final interface with the transporter's
installations, will now be a standard requirement for
all new wind farm sites being connected to HydroQuebec's network in the next few years.
Advantages:
• Remote access to the IEDs directly (configuration,
perturbograph, state of communication, …)
• Flexibility in the calculations that could not be done
into the wind turbine SCADA or the Substation
SCADA.
• Possibility to either use the Substation SCADA as a
Central SCADA or add a 3rd SCADA systems to
interface directly with the gateway and be the Central
points of the operators.
• Time Latency < 500 ms end to end.
• This approach covers both the Transporter's and the
Producer's needs.
Example of requierement in term of
Time Latensy of the critical information
Transmission
time from site
to EMS
(< 100 ms)
0
ms
100
ms
200
ms
Device
reaction
time
(< 200 ms)
300
ms
400
ms
500
ms
RTU
processing
time
(< 500 ms)
600
ms
700
ms
800
ms
900
ms
Gateway
processing
time
(< 200 ms)
1
s
Martin Boulay, Eng.
Robert O’ Reilly
Automation Engineer
The Ohmega Group Inc
3, des Cerisiers Street
Gaspe (Quebec) G4X 2M1
Phone: 418 368-5425 ext. 38
Fax: 418 368-7290
mboulay@groupeohmega.com
Senior Application Engineer
Cooper Power Systems - Cybectec
Energy Automation Solutions
1290, St. Denis Street
Suite 400
Montreal (Quebec) H2X 3J7
Phone: 418 845-6195 ext. 244
Fax: 514 227-5256
robert.oreilly@cybectec.com